Year Number 1970 219046.03125 1971 227369.375 1972 234509.84375 1973 238260.296875 1974 241824.46875 1975 248080.25 1976 244034.8125 1977 244717.15625 1978 245228.078125 1979 244519.484375 1980 245655.84375 1981 244485.8125 1982 245942.390625 1983 251584.3125 1984 258038.625 1985 264036.34375 1986 269491 1987 274480.1875 1988 280705.15625 1989 286364.40625 1990 289879.78125 1991 294003.84375 1992 299665.5 1993 308186.4375 1994 312065.71875 1995 313746.34375 1996 302766.9375 1997 314542.40625 1998 311642.34375 1999 302689.125 2000 302521.3125 2001 310377.34375 2002 314700.75 2003 318851.78125 2004 320564.40625 2005 321105.375 2006 322364.5 2007 318490.90625 2008 321286.0625 2009 322327.15625 2010 330037.46875 2011 332422.21875 2012 333905.21875 2013 340626.03125 2014 345744 2015 350556.90625 2016 358265.6875 2017 366511.21875 2018 370362.03125 2019 378191.1875 2020 376595.15625 2021 381658.3125